Control device for engine driven generators



Sept. '26, 1933. H. D. GUMPPER 1,928,152

CONTROL DEVICE FOR ENGINE DRIVEN GENERATORS Filed-Jan. 22, 1931 F""""" Il INVENTOR ATTO RN EYS Patented Sept. 26, 1933 PATENT OFFICE "(CONTROL,DEVICE FOR ENGINE DRIVEN GENERATORS Harold D. Gumpper, Detroit, Mich.,assignor to Marjorie Teakle Gumpper, Detroit, Mich.

Application January 22, 1931. Serial No. 510,500

Claims. (Cl. 290-17) This invention pertains to means for controllingthe speed of a prime mover in driving an electric generator, in such a.manner that the speedof the prime, mover will be much slower 5whenjelectric power is not being used, and may be automaticallyincreased upon the application of an external electrical loador upon themanual closing of an externalcontrol switch. This is accomplished bymeans of a voltage regulating device consisting of an electricalgovernor capable of maintaining both a constant high operating voltageand a constant low no load voltage. Thus, where the load isintermittent, saving of power as well as wear on the prime mover andelectric generator are possible, due tothe much slower speed of theprime mover when operating the generator at no load voltage.Furthermore, due to the maintained no load voltage'being held constantby the electric governoryvoltage pick up of the 20 generator uponapplication of an external load is much more rapid than wouldotherwiseresult if the generator voltage fell too low at no load.

A further objectis to provide a simple device for the purpose, notliable to get out of order and which may be readily applied in use, andhaving certain other new and useful features, hereinafter set forth andall as moreparticularly pointed out in the appended claims, referencebeing had to the accompanying drawing in which- Figure 1 isasideelevation of an internal combustion engine, the crankshaft ofwhichis direct connected to' an electric generator indicated in dottedlines, and showing in elevation, a governor and the manner of.connecting the same to the engine and also showing its electricalconnections to the generator and to a motor indicated in outline anddriven by generator output current; and

Fig. 2 is a longitudinal section through a governor and showing itsconnection to a throttle device of the engine with its electricalconnections to motor and generator indicated diagrammatically.

As shown in Figure 1, A indicates a prime mover or internal combustionengine of the usual construction, having the usual crank shaft Bindicated in dotted lines and to which an electric generator C of theusual construction and also indicated in dotted lines, is directconnected in Lin 5 any suitable manner. The engine A is provided withthe usual intake manifold D to which a carbureter E is connected in theusual manner.

To control the voltage output of the generator C, the speed of theengine A is controlled by an electric governor, indicated as a whole bythe numeral 1, which is rigidly supported in any suitable manner at oneside of the engine adjacent the uptake pipe of the manifold D and inwhich pipe is a throttle valve 2 indicated in dotted lines andto theouter end of the stem of which throttle, is secured a lever 3. Thislever is connected at its free end by a link 4, with one end of aplunger or movable core member 5 slidable within an axial guide tube 6in the casing 7 of the governor and in which casing are mounted twosolenoids or wire coils, one within the other, the inner coil 8 beingwound about the tube 6, and the outer coil 9 wound about and insulatedfrom the inner coil 8. One end of the axial tube 6 is provided with ascrew 12 which passes through the closed end of the tube and bearsagainst a stop 11, which in turn bears against one end of a compressionspring 10. A lock nut 13 is provided for clamping the screw 12in anydesired position. The other end of the compression spring bears againstthe plunger 5, tending to move it axially out of tube 6 and therebycausing lever 3 to move throttle valve 2 from a closed to an openposition.

Coil member 8 is shown as electrically connected in shunt with thegovernor C to line 17 which leads to terminal of the governor, and toline 18 which leads-to terminal 16 0f said governor. Thus, when thisgenerator armature is revolving, an electrical current will pass throughcoil member 8- forming a solenoid efiect which will tend to move theplunger 5 axially into the tube 6, against the action of spring 10. Thebalance that is established'between the solenoid action of the coil 8upon plunger 5 and of spring 10 acting against plunger 5 will controlthe opening of throttle 2. As the voltage of the generator increases,the magnetic pull of solenoid coil 8 increases, moving the plungerinward against the spring, and as the voltage of the generator falls01f, the pull of solenoid 8 weakens and the spring 10 moves the plungeroutward. Thus the speed of engine A is controlled by the voltagegenerated at terminals 15 and 16 of the generator.

In order that the generated voltage across terminals 15 and 16 of thegenerator C may be increased upon the application of an external load, Ihave provided an additional winding on the governor 1, shown as coil 9in Figure 2. An external load shown as a motor indicated by 14 in Figure2 is connected by means of line 19 to terminal 15, and by line 20 toterminal 16 of the generator.

A switch, shown as 23, is inserted in line 20 to open and close themotor circuit. Coil 9 is connected by means of line 22 to terminal 15 ofthe generator and by line 21, which leads as shown to a point in line 20between switch 23 and the motor 14. The polarity of leads 21 and 22coming out of coil 9 are such that when switch 23 is closed, themagnetic field set up by coil 9 opposes the magnetic field of coil 8.Thus, the resultant magnetic pull when coil 9 is energized, is smallerthan where coil 8 only is in operation. Thus when both coils 8 and 9 areenergized, the spring 10 moves plunger 5 out of tube 6 and the throttle2 is opened, increasing the speed of the engine and building up a highervoltage across the terminals of the generator 15 and 16. As this voltagebuilds up, a new balance between the combined magnetic fields of coilsSand 9 and the spring 10 will be established and the throttle 2 willcome to rest in such a position that a higher operating speed of theengine will result, and consequently a higher voltage will be generated.Opening of switch 23 will cause coil 9 to lose its magnetic field andcoil 8 will then act at full strength and the engine speed will bereduced to that occurring before the switch was closed.

Obviously changes may be made in the electrical connections and in theparticular construction and arrangement of coils 8 and 9, theirconnections, and in the plungers and their connections, also in otherparts without departing from the spirit of the invention, and suchchanges are contemplated.

Having thus fully described my invention, what I'claim is:-

1. An electric governor for controlling the speed of a prime moverarranged to drive an electric generator, said governor comprising amovable core, two electric coils arranged to act magnetically upon saidmovable core, and resistance means to resist movement of said core, oneof said coils connected in shunt with the terminals of said generator,and the other of said coils having a shunt connection with an externalcircuit, upon closing of said external circuit and acting magneticallyin opposition to the first of said coils, and control means for varyingthe speed of said prime mover and means for connecting said core andsaid control means.

2. The combination with a prime mover, an electric generator driven bysaid prime mover, an electric motor electrically connected to saidgenerator to receive current therefrom, and a control device for saidprime mover; of an electric governor comprising a solenoid having alongitudinally movable core and two coils, one within the other,encircling said core and arranged, one

to decrease the magnetic effect of the other upon said core, said coilsbeing separately connected in shunt across said generator and said motorcircuit, and means for operatively connecting said core and controldevice.

3. The combination with a gas engine having an intake manifold, acontrol valve in said manitold, an electric generator direct commuted tosaid engine to be driven thereby, an electric motor having an operatingswitch in the leads from said generator to said motor to supply currentto said motor from said generator; of an electric governor comprising asolenoid having a movable core, and two concentric coils encircling saidcore, one of said coils being electrically connected in shunt across theterminals of said generator and the other of said coils beingelectrically connected in shunt across the leads to said motor and beingenergized by the closing of said switch, a spring to move said core inone direction, and means connecting said core and said control valve tooperate said valve by the longitudinal movement of said core.

4. An electric governor for controlling the speed of a prime moverarranged to drive an electric generator, an electric motor connected tosaid generator to receive current therefrom, said governor comprising amovable core, two electric coils arranged to act magnetically upon saidmovable core, and resistance means to resist movement of said core, saidcoils being arranged, one to decrease the magnetic efiect of the otherupon said core, said coils being separately connected in shunt acrosssaid generator and motor circuits, and control means for varying thespeed of said prime mover and means for connecting said core and saidcontrol means.

' 5. An electric governor for controlling the speed of a prime moverarranged to drive an electric generator, said governor comprising amovable core, two electric coils arranged to act magnetically upon saidmovable core, and resistance means to resist movement of said core, oneof said coils being connected in shunt with the terminals of saidgenerator, and the other of said coils connected in shunt with anexternal circuit for energization through the closing of a manuallyoperated switch in said external circuit and acting magnetically inopposition to the first of said coils, and control means for varying thespeed of said prime mover, and means for connecting said core and saidcontrol means.

HAROLD D. GUMPPER.

